We describe two splenectomized patients admitted with pneumonia. The course in one was complicated by overwhelming multiorgan failure when the only indicative laboratory result was seropositivity for Legionella hackeliae and Legionella longbeachae. He was initially treated with ceftriaxone and roxithromycin, followed by levofloxacin as well as intensive supportive treatment, and survived. The second patient was seroreactive for Legionella micdadei. In some cases of pneumonia in splenectomized patients tentatively considered to be caused by Streptococcus pneumoniae, the causative agent might have, in fact, been Legionella. We suggest that splenectomy be considered a possible predisposing factor for Legionella pneumonia. Since prompt diagnosis of Legionella infection, especially the non-pneumophila species, is extremely difficult, alertness to this diagnostic option and early empirical initiation of appropriate aggressive antibiotic treatment may be of critical importance.